Transmission and transmission housing with multiple dipsticks and dipstick apertures, circumferentially positioned internal lugs and an adjacent fluid inlet port

ABSTRACT

A transmission housing, or transmission including a transmission housing, having a plurality of dipstick access ports positioned on the housing for receiving in each access port a dipstick that is used to monitor a level of transmission fluid in an oil pan mounted to a bottom of the transmission housing. The housing may also include internal lugs positioned along an internal surface of the housing that interlock or interconnect with a transmission component to minimize rotational movement of the component relative to the housing. The lugs are aligned and spaced equidistance apart circumferentially on the internal surface of the housing, thereby eliminating larger gaps between consecutive lugs, which may concentrate mechanical stresses on the lugs at such a gap, as in prior art transmission. In addition, the housing may include an inlet fluid port positioned adjacent the lugs for receiving cooled transmission fluid to lubricate and cool centrally and rearwardly positioned transmission components.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/567,211 filed Dec. 6, 2011, and incorporated herein by reference inits entirety.

BACKGROUND OF THE INVENTION

This invention generally relates to transmissions for marine and landvehicles and machines and more particularly to transmission housingsused to house the components of transmissions. More specifically, theinvention pertains to transmission fluid dipsticks used in connectionwith a transmission to determine levels of transmission fluid availablefor operation of the transmission. Another aspect of the inventionrelates to internal lugs that are circumferentially spaced on aninternal surface of the transmission housing for securing in placecomponents of a transmission. In addition, the invention pertains toinjection additional cooled transmission fluid into the transmissionhousing.

Dipsticks for Transmission Housings

Automatic transmissions comprise a series of gears, shafts, clutches,valves and hydraulic controls housed within a transmission housing orcasing. The transmission is connected at its front end to an enginecrankshaft and flexplate via a torque converter. At its back end, thetransmission is connected to an output shaft, which transmits rotarypower generated by the engine and transmission to wheel axles, via auniversal joint, in the case of an automobile transmission. Such similartransmission arrangements are available for marine vehicles andmachinery that include transmissions in combination with engines togenerate rotary power.

In such transmissions, an oil pan is mounted and sealed to a bottom ofthe housing, and provides a reservoir for automatic transmission fluidused to operate the transmission. An oil pump, which is typicallypositioned toward a front of the transmission housing, is in fluidcommunication with the oil pan and an interior of the housing via aseries of fluidic channels and one or more valve bodies. The oil pumpsupplies the transmission fluid (oil) under pressure to actuate thevarious clutches inside the housing in order to transmit power from theengine to the axles and wheels.

To insure that a sufficient amount of transmission fluid is present inthe transmission oil pan, the transmission includes a fluid leveldetection device that is manually inserted either through thetransmission housing or the oil pan to detect a level of transmissionfluid in the oil pan. The most commonly used device is a dipstick, whichis inserted through an access port disposed on a side of thetransmission housing and extends into the oil pan. Such a dipstickincludes a handle fixed to a thin metal strip that has been stamped withfluid level markings. The metal strip passes through the access port,which includes a raised aperture on the housing and a guide tubepositioned at the aperture and fixed to the transmission housing. Asindicated above, the access port is typically positioned on a side ofthe housing (for an automobile, that is the passenger side or driverside) and the dipstick is long enough to allow the top of the dipstickto be positioned at a location that is accessible by hand and convenientfor checking.

A less common placement of the dipstick is at the oil pan instead ofdipstick passing through the transmission housing. In order to obtain anaccurate reading of the transmission fluid level the access port ispositioned relatively low on the oil pan. This leaves the dipstickvulnerable to damage as the bottom of the vehicle is exposed andunprotected to road debris. The dipstick and or guide tube can easilysnag road debris and become dislodged or ripped from the access port,which then drains the transmission fluid from the oil pan, potentiallycausing catastrophic failure of the transmission. When the dipstick tubeis installed in the transmission housing, it is in a protected area thatlies between the transmission housing and the floorboard/firewall of thevehicle so damage from road debris rarely occurs.

Another reason tubes are rarely attached to the oil pan involvesservicing of the transmission. Transmissions are serviced (maintained)by removing the oil pan, cleaning and flushing the inside of thetransmission, and then changing the oil filter. When the guide tube isattached to the oil pan, the oil pan cannot be easily removed becausethe dipstick and/or the guide tube hangs up or attaches to parts orareas in the engine compartment. This makes servicing more difficult andtime consuming. Conversely, the dipstick and guide tube do not have tobe removed during services when attached to the transmission housing;and, a technician simply unbolts and removes the oil pan to perform therequired maintenance. Accordingly, the dipstick has been predominantlyand traditionally positioned along one of the two sides (primarily thepassenger side) of the transmission housing.

However, this traditional placement of the dipstick is not without someshortcomings. More specifically, in competitive or modified vehiclesthat incorporate original equipment manufacturer (OEM) transmissions,the position of the transmission and transmission housing relative tothe engine, engine compartment and/or firewall may be different ascompared to OEM vehicles for which the OEM transmission was designed. Inaddition, after market manufacturers of transmission housings that areused in competitive and modified vehicles generally follow the OEMspecifications of the transmission housings and have maintained thetraditional placement of the dipstick and guide tube on the passengerside of a vehicle. Accordingly, access to the dipstick may becompromised and difficult to reach.

Internal Lugs for Transmission Housings

The Hydra-Matic 400 transmission, manufactured by General Motors®, andits transmission housing are oftentimes used in competitive vehicles,for example, drag racing vehicles and off-road desert racing vehicles.The transmission housing includes lugs (also sometimes referred to assplines or teeth) that are spaced apart equidistance on an internalsurface of the housing. These lugs interconnect with lugs of atransmission component to minimize rotational movement of the componentrelative to the transmission housing.

While the lugs on the housing are spaced generally circumferentially onthe internal surface of the housing, the lugs do not expand the entireinternal circumference of the housing. That is, a gap is disposedbetween two end lugs wherein the gap is larger than the spacing betweenconsecutive lugs. This gap is represented by the square 40 shown in FIG.5, which is a drawing of the subject invention including lugs at thelocation of the gap. This gap was provided for ease and speed ofmanufacturing of the transmission.

A pocket (shown in FIG. 5) is formed in the internal surface of thehousing adjacent the lugs to support a component of the transmissionhousing adjacent to the set of lugs and the gap. During the course ofmanufacturing of the prior art Hydra-Matic 400 transmission housing, acore or plug is fixed relative to an external mold. This plug includesvarious projections, protrusions, recesses, voids, channels, etc.,representing structural features of the housing that are positioned inmating relationship with matching features on the external mold. Theexternal mold surrounds the plug to form the housing. After the housingis formed between the external mold and the plug, the external mold isremoved. A protrusion forming the pocket actually extends forward to anend of the plug so the pocket on the housing extends to the end of thehousing. In this manner, the plug can be removed from the formedtransmission housing. However, if lugs were formed in the gap, the lugswould block the protrusion on the plug forming the pocket and the plugcould not be removed. Accordingly, additional steps in the manufacturingprocess would be required if lugs were to be formed at the gap.

It is known that, at least with respect to the use of this transmissionhousing in competitive vehicles as described above, the existence of thegap compromises the structural integrity of the transmission housing. Asnap ring is disposed within a slot aligned in each of the lugs, andmoving transmission components bump or push against the support ringcausing mechanical stress on the lugs. Two end lugs at the gap absorbadditional stresses in the absence of the lugs at the gap. As the endlugs at the gap are exposed to additional stresses, they tend to crackor break first, especially in the above-described competitive vehicles.When the end lugs crack or break off this causes what may becharacterized as a chain reaction, in which the next consecutive lugeventually breaks and so on until a sufficient number of lugs breakdestroying the locking interconnection between the transmission and thetransmission housing.

As this problem with the Hydra-Matic 400 transmission is well-known tothose skilled in the art, some after-market parts manufacturers make andsell parts such as intermediate tabs, supports or plates that are fixedto the internal surface at the gap between the two end lugs. Thisadditional part better distributes the stresses along the lugs toprevent the lugs from breaking. Moreover, not all transmission housingsinclude the above-described gap between the two end lugs. For example,the transmission housings for an Allison AT542 transmission, which havebeen manufactured at least as early as 1980, include lugs that arespaced equidistance apart and are positioned circumferentially 360°along an interior surface of the housing, and does not include theabove-described gap. However, the transmission housing for the AT542, orany other transmission housing designed specifically for anothertransmission, obviously will not fit a Hydra-Matic 400 automatictransmission, which is an extremely popular transmission for competitiveracing and off-road vehicles.

Injection of Cooled Transmission Fluid into Housing

Under extreme conditions, gear train parts of a transmission musttransmit higher levels of power thru the transmission. The higher powerlevels result in more forces being applied to the various gear trainparts. Higher forces create more load and friction on the parts. Thisbreaks down the transmission fluid or lubricating oil causing great wearor galling of the parts eventually leading to failure. The loadingcaused friction also heats up the parts, which breaks down thelubricating properties of the transmission fluid thereby creating evenmore wear, heating, and friction in an endless downward spiral until theentire transmission fails.

In the OEM transmission applications, oiling and cooling is accomplishedby taking pressurized transmission fluid from the torque converter andsending it out to an external cooler via a hose connected to a fittingon the side of the transmission housing. The transmission fluid returnsfrom the cooler in a much cooler state and is injected back into thetransmission case via a second hose and fitting in the side of thetransmission case that is located near the first fitting and hose towarda front of the housing. This cooled transmission fluid is conducted thruthe shafts and gears throughout the gear train. It eventually is sprayedout thru openings in the shafts, gears, clutches and drums and it drainsdown into the oil pan at the bottom of the transmission. Thistransmission fluid cools and lubricates the various parts inside thetransmission and works adequately under normal transmission use.

In severe duty applications, not enough oil reaches the rear of the geartrain to cool and lubricate the parts, because the cooled transmissionfluid is introduced toward the front of the housing. General Motors®recognized this problem and in a next generation of transmissions calledthe 4L80E that succeeded the Hydra-Matic 400, the location of the returnoil line was moved to a more central location. The intermediate(sometimes called the center) support housing which is the part thatmates to the above-mentioned lugs inside the transmission case, has anadditional oil passageway present that allows oil to be transmitted fromthe outside of the case to the inside gear train section. The 4L80Etransmission has been manufactured since the 1990's.

In a effort to make the Hydra-Matic 400 live longer under extremeconditions, it is well-known in the industry (particularly the off-roadracing industry) that an additional external oil cooling line may beplumbed into the intermediate support housing. Two companies that havebeen making this modification to the Hydra-Matic 400 for many years areRancho Drivetrain Engineering in Temecula, Calif., and Gearworks in LasVegas, Nev. This is accomplished by drilling and threading theadditional oil hole duplicating the 4L80E arrangement. One shortcomingwith this procedure is that the casting is very thin where theadditional oil fitting is added, so care must be used in installing andproperly supporting the extra oil line.

BRIEF DESCRIPTION OF THE INVENTION

Accordingly, a feature of the present invention is to include with atransmission housing, or transmission including a transmission housing,a plurality of dipstick access ports positioned on the housing forreceiving in each access port a dipstick that is used to monitor a levelof transmission fluid in an oil pan mounted to a bottom of thetransmission housing. The oil pan holds the transmission fluid that isdeliverable under pressure for actuation of one or more of transmissioncomponents encased within the housing. The feature of multiple dipstickaccess ports may be especially beneficial for transmissions used inracing vehicles that include transmissions that are positioned relativeto an engine that may make a single dipstick and access portinaccessible.

Another feature of the invention includes the positioning of internallugs along an internal surface of the housing that interlock orinterconnect with a transmission component to minimize rotationalmovement of the component relative to the housing. The lugs are alignedand spaced equidistance apart circumferentially on the internal surfaceof the housing, thereby eliminating larger gaps between consecutivelugs, which may concentrate mechanical stresses on the lugs at such agap, as in prior art transmission. Also, the additional lugs eliminatethe need for after-market parts that are mounted to the housing tocompensate for the absence of lugs.

Yet another feature of the invention includes positioning a fluid inletport in the housing adjacent the location of the internal lugs.Transmission fluid drawn from a torque converter or a front of thetransmission is directed to a cooler via a line and the cooledtransmission fluid is injected into the housing through the fluidinjection port positioned adjacent the internal lugs. In an embodiment,the fluid injection port includes a raised boss to support a fitting forattachment of the fluid line. In this manner, cooled transmission fluidmay be injected into the housing to both cool and lubricate transmissioncomponents centrally and rearwardly located in the transmission.

BRIEF DESCRIPTION OF THE DRAWINGS

A more particular description of the invention briefly described abovewill be rendered by reference to specific embodiments thereof that areillustrated in the appended drawings. Understanding that these drawingsdepict only typical embodiments of the invention and are not thereforeto be considered to be limiting of its scope, the invention will bedescribe and explained with additional specificity and detail throughthe use of the accompanying drawings.

FIG. 1 is a top view of a transmission housing with a plurality ofdipstick access ports.

FIG. 2 is a bottom partial sectional view of the transmission housingwith an oil pan being removed to view the multiple dipstick accessports.

FIG. 3 is a side view of the transmission housing with an oil panattached and the dipstick and guide tube shown.

FIG. 4 is a first sectional view of the transmission housingillustrating the internal lugs.

FIG. 5 is a second sectional view of the transmission housingillustrating the internal lugs.

FIG. 6 is a side view of the transmission housing illustrating a fluidexit port and two fluid inlet ports and corresponding fluid lines, withone of the fluid inlet ports positioned adjacent the internal lugs.

FIG. 7 is an internal sectional view of the transmission housingincluding a fluid inlet port adjacent the internal lugs.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the embodiments consistent withthe invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numerals are usedthroughout the drawings and refer to the same or like parts.

With respect to FIG. 1, a transmission 10 is shown including atransmission housing 11 with its front end 15 connected to an engine 12via a torque converter 14 and flexplate 13. The transmission 10 includesthe housing 11 and transmission components 17 (schematically shown),such as gears, clutches, shafts, valve bodies, etc., which are encasedwithin the housing 10 and transmit rotary power generated by the engine12 to an output shaft and an axle (not shown).

As shown in FIG. 3, an oil pan 28 is mounted to a bottom of thetransmission housing 11. More specifically, the housing 11 includes aflange 27 at a bottom of the housing 11; and, the oil pan 28 includes amatching flange that is bolted to the flange 27 of the housing 11. As inconventional transmissions, the oil pan 28 serves as a reservoir fortransmission fluid. To that end an oil pump (not shown) may be providedto transfer transmission fluid under pressure from the oil pan 28through fluidic channels 29 and valves to actuate components (clutches)of the transmission 10. In FIG. 2, a portion of the transmission fluidcontrol assembly 31 is removed showing the fluidic channels 29 andmounts 30 for valve bodies.

As shown in FIGS. 1 and 2, the housing 11 includes a plurality ofdipstick access ports 21A, 21B. In a preferred embodiment, a pluralityof dipsticks 24 may be used wherein each dipstick 24 is inserted into acorresponding access port 21A, 21B. Each access port 21A, 21B includesan aperture 22 and a guide tube 23, through which the dipstick 24 isinserted. As known to those skilled in the art, the guide tube 23includes a collar 36 such that when the tube 23 is inserted into theaperture 22, the guide tube 23 is positioned in sealing relationshipwith the aperture to prevent leakage of transmission fluid from thehousing 11 or oil pan 28.

In addition, the dipstick 24 is of a conventional design including anelongated metal strip 32 with stamped markings for measuring a level oftransmission fluid in the oil pan 28. The dipstick also includes ahandle 33 for grasping the dipstick 24 when inserting or removing thedipstick 24. Although it is preferred, a dipstick 24 is not required foreach access port 23. As described below, when the transmission 10 withthe housing is installed one of the access ports 21A or 21B that is moreaccessible than the other may be selected as a preferred access port fora dipstick 24, and the other access port 21A or 21B may be sealed shutto avoid leakage of transmission fluid.

In the embodiment illustrated in FIGS. 1-3, and described herein, thehousing 11 includes two access ports 21A, 21B; however, the invention isnot so limited and may include more than two access ports. As shown, thedashed line 18 represents a centerline of the housing 11 therebydividing the transmission longitudinally wherein the housing 11 includesa first side 19 and a second side 20. Accordingly, one access port 21Ais on a first side 19 and the other access port 21B is on the secondside 20 of the transmission housing 11. However, the access ports 21Aand 21B do not have to be positioned on opposite sides of the housing11, and may be positioned on the same side of the housing 11.

The above-described housing 11 may be incorporated with a transmission10 that is used in a competitive racing vehicle, such as a drag racingor off-road desert racing vehicle. Similarly, the housing 11 may beequipped for a marine racing vehicle. In such vehicles, the engine andother parts may require positioning the transmission 10 and housing 11within the vehicle frame such that the conventional position of adipstick 24 and access port 21B, on the passenger side (second side 20)of the vehicle, is not readily accessible. Accordingly, the presentinvention for the transmission 10 and transmission housing 11 havingmultiple dipstick access ports 21A, 21B provides multiple areas ofaccess to a dipstick to monitor transmission fluid levels that may nototherwise be available for a transmission that includes only a singledipstick access port.

In addition to the above-described multiple dipstick access ports 21A,21B the transmission housing 11 includes internal lugs 34 positioned onan internal surface of the housing 11. These lugs 34 interface orinterlock with one or more components of the transmission to minimizerotational movement of the component relative to the housing. Forcertain transmissions, such as the Hydra-Matic 400 manufactured byGeneral Motors®, the transmission housings included a gap between twoend lugs. As described above, this gap was generally the vestige of amanufacturing/molding process; however, the existence of the gapcompromised the structural integrity of the lugs 34 and housing 11.

Accordingly, with respect to an embodiment of the present invention, thetransmission housing includes lugs 34 positioned at the location ofpreviously described gap. That is, the lugs 34 are positionedcircumferentially along an internal surface of the housing 11, spacedequidistance apart from one another and are aligned side by side. Thus,the above-described gap is eliminated whereby the spacing betweenadjacent lugs 34 is substantially equal along an internal circumferenceof the housing 11. For example, a transmission housing 11 manufacturedto fit a Hydra-Matic 400 transmission may include twenty-two lugs thatare each ½″ wide, and adjacent lugs are spaced apart ½″. In addition,the lugs 34 are each about 2″ long, including a ¼″ long lip forming aslot for inserting a snap ring. By including the additional lugs 34 atthe gap, the mechanical stresses on the lugs from operation of thetransmission is more evenly distributed among the lugs 34 as opposed toconcentrating some stresses on a few of the lugs 34. Accordingly, thestructural integrity of the housing 11 is not compromised as in theabove-described prior art housings. The transmission housing 11 ismanufactured using known molding techniques and materials such as a castaluminum alloy.

In reference to FIGS. 6 and 7, in addition to the above-describedmultiple dipstick ports 21A, 21B and internal lugs 34, the transmissionhousing 11 may include a fluid inlet port 35 (second inlet port) towardthe rear end 16 of the housing 11 and adjacent to the internal lugs 34for injection of cooled transmission fluid into the housing to cool andlubricate transmission components. The internal sectional view shown inFIG. 7 illustrates the positioning of the second inlet port 35 adjacentto the lugs 34.

As shown in FIG. 6, the housing 11 includes a fluid outlet port 37positioned at the front end 15 of the housing and a corresponding outletline 38 that directs transmission fluid from an interior of the housing11 to an external cooler for cooling the hot transmission fluid. Aninlet line 39 circulates the cooled transmission fluid from the coolerto a first inlet port 41 that is adjacent to the outlet port 37 at thefront end 15 of the housing 11.

As illustrated in FIG. 6, a T-fitting 42 at the first inlet port 41allows the inlet line 39 to continue to the second inlet port 35 socooled transmission fluid can be injected at a central location of thehousing adjacent the internal lugs 34. However, a t-fitting is notrequired at the first inlet port 41 to circulate the cooled transmissionfluid both inlet ports 35, 41. For example, the t-fitting 42 may bepositioned upstream along the line 39 toward the cooler to split theline 39 for injection in both ports 35, 41, or other plumbingconfigurations may be used to direct cooled transmission fluid to bothinlet ports 35, 41.

As described above, the original OEM design Hydra-Matic 400 transmissionhousings included a fluid outlet port at the front end of the housing, afluid inlet port adjacent to the outlet port and corresponding lines tocirculate transmission fluid past or through a cooler for introductionof cooled transmission fluid into the transmission. As also described,for competitive racing, especially off-road racing vehicles, it is knownthat these OEM housings are modified to include a second inlet port thatis generally centrally located on a side of the housing, or adjacent aset of internal lugs. However, the OEM castings are very thin at thislocation of the additional fitting, so care must be used in installingand properly supporting the extra oil line.

Accordingly, in an embodiment of the invention the second inlet port 35includes a raised boss 43. By way of example the boss 43 may protrudeout of an outer wall of the housing about ½ inch and is of sufficientdiameter to allow the machining and thru drilled hole to the inside ofthe housing, as well as supporting a fitting to attach line 39 to thesecond inlet portal 35. Thus, an embodiment of the subject invention mayinclude the above-described mechanism for introducing cooledtransmission fluid into an interior of the housing to cool and lubricatetransmission components adjacent to the internal lugs to cool andlubricate centrally and rearwardly located transmission components.

While the preferred embodiments of the present invention have been shownand described herein, it will be obvious that such embodiments areprovided by way of example only and not of limitation. Numerousvariations, changes and substitutions will occur to those skilled in theart without departing from the teaching of the present invention.Accordingly, it is intended that the invention be interpreted within thefull spirit and scope of the appended claims.

The invention claimed is:
 1. A transmission assembly comprising: asingle transmission housing having an interior in which a plurality oftransmission components are capable of being positioned; a single oilpan mounted to a bottom of the single transmission housing for holding atransmission fluid that is deliverable under pressure to the interior ofthe housing; and a plurality of dipstick access ports positioned on thesingle transmission housing for receiving in each access port a dipstickthat is used to monitor a level of the transmission fluid in the singleoil pan.
 2. The transmission assembly of claim 1, wherein the housingincludes a centerline coextensive with a longitudinal axis of thehousing dividing the housing into a first side and a second side whereinat least one dipstick access port is on the first side and at least onedipstick access port is on the second side.
 3. The transmission assemblyof claim 1, wherein the housing includes a centerline coextensive with alongitudinal axis of the housing dividing the housing into a first sideand a second side wherein the plurality of dipstick access ports are oneither the first side or the second side.
 4. The transmission assemblyof claim 1, further comprising at least one dipstick inserted through acorresponding access port.
 5. The transmission assembly of claim 1,further comprising a flange positioned toward the bottom of the housingand the oil pan is mounted to the flange, wherein each of the pluralityof dipstick access ports is positioned on the flange.
 6. Thetransmission assembly of claim 5, wherein the housing has a generallycylindrical shape and a plurality of lugs are positioned on an internalsurface of the housing spaced equidistance apart from one another,aligned with each other and are disposed circumferentially along theinternal surface of the housing.
 7. The transmission assembly of claim6, further comprising an outlet transmission fluid port and line throughwhich transmission fluid from the interior of the housing to a coolervia the outlet line, and an inlet transmission fluid port and linethrough which cooled transmission fluid passes into the interior of thetransmission housing to cool and lubricate transmission components,wherein the inlet transmission port is positioned adjacent to theinternal lugs.
 8. The transmission assembly of claim 7, wherein theinlet transmission fluid port positioned adjacent the internal lugs is afirst inlet port and the housing further comprises a first transmissioninlet port adjacent to the outlet transmission fluid port at a front endof the transmission housing.
 9. The transmission assembly of claim 7,wherein the inlet transmission fluid port includes an externallyprotruding boss for supporting a fitting and attachment of inlettransmission fluid line.
 10. The transmission assembly of claim 1,wherein the plurality of dipstick access ports include at least twodipstick access ports for the single oil pan in the transmissionhousing.
 11. The transmission assembly of claim 1, wherein the singleoil pan is mounted to the bottom of the single transmission housingbased on a flange at the bottom of the single transmission housing beingbolted to a matching flange of the single oil pan.
 12. A transmissionconnected to a crankshaft of an engine for transmitting a rotationalpower output generated by the engine to an axle, the transmissioncomprising: a single transmission housing having an interior in whichtransmission components are positioned; a single oil pan mounted to abottom of the single transmission housing for holding a transmissionfluid that is deliverable under pressure for actuation of one or moretransmission components; a plurality of dipstick access ports positionedon the single transmission housing; and, a plurality of dipstickswherein each dipstick is inserted into a corresponding dipstick accessport and partially submersed in the transmission fluid for monitoringlevels of the transmission fluid.
 13. The transmission of claim 10,wherein the single transmission housing includes a centerlinecoextensive with a longitudinal axis of the housing dividing the housinginto a first side and a second side wherein at least one dipstick accessport is on the first side and at least one dipstick access port is onthe second side.
 14. The transmission of claim 10, further comprising aflange positioned toward the bottom of the housing and the oil pan ismounted to the flange, wherein each of the plurality of dipstick accessports is positioned on the flange.
 15. The transmission of claim 10,wherein the housing has a generally cylindrical shape and a plurality oflugs are positioned on an internal surface of the housing spacedequidistance apart from one another, aligned with each other and aredisposed circumferentially along the internal surface of the housing.16. The transmission of claim 14, further comprising an outlettransmission fluid port and line through which transmission fluid fromthe interior of the housing to a radiator via the outlet line, and aninlet transmission fluid port and line through which cooled transmissionfluid passes into the interior of the transmission housing to cool andlubricate transmission components.
 17. The transmission housing of claim15, wherein the inlet transmission fluid port positioned adjacent theinternal lugs is a first inlet port and the housing further comprises afirst transmission inlet port adjacent to the outlet transmission fluidport at a front end of the transmission housing.
 18. The transmissionhousing of claim 15, wherein the inlet transmission fluid port includesan externally protruding boss for supporting a fitting and attachment ofinlet transmission fluid line.
 19. The transmission of claim 10, whereinat least one of the dipsticks is inserted through at least one of theplurality of dipstick access ports and wherein at least one of thedipsticks is not inserted through at least one of the plurality ofaccess ports that is sealed shut.